Objective: To study the mechanisms of assembly and uncoating of adenovirus virions. Approach: The assembly process will be explored through the use of a number of type 5 adenovirus, conditionally lethal, temperature- sensitive mutants which are defective in: assembly, hexon transport; hexon protein; and fiber protein. Experiments will also be pursued to study the fate of the core internal proteins associated with viral DNA in preparation for early transcription and replication of the viral genome. The nucleoprotein cores will be obtained by isolation of those assembled in cells infected with the above mutants at the non-permissive temperature (39.5 degrees C) or they will be prepared artificially from purified virions.